Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Physical Chemistry
442 practice questions
Topics covered
Practice questions
301–310 of 442
Question 301
3 marks · Easy
Answer and see the solution →This question is about sealed containers and reversible reactions.
(a)[1 mark]State what a sealed container means in the context of a chemical reaction.
(b)[1 mark]Give one reason why using a sealed container is important when studying reversible reactions.
(c)[1 mark]Suggest one thing that is allowed to change in a sealed container during a reaction.
Question 302
2 marks · Easy
Answer and see the solution →The thermal decomposition of solid ammonium chloride is a reversible reaction.
Explain why both ammonia and hydrogen chloride gases are observed inside the sealed tube during heating, and why a white solid appears again above the heated area.
Question 303
3 marks · Easy
Answer and see the solution →A student records the number of red and green squares at different times in a sealed container during a reversible reaction.
Time (s) Red squares Green squares 0 40 0 1 30 10 2 23 17 3 19 21 (a)[1 mark]How many total squares are there in the container at each recorded time?
(b)[1 mark]What does this suggest about the system in the container?
(c)[1 mark]State what feature of the container ensures this result in a reversible reaction.
Question 304
1 mark · Easy
Answer and see the solution →State what term is used when the rate of the forward reaction equals the rate of the backward reaction in a sealed system.
Question 305
3 marks · Easy
Answer and see the solution →When heating ammonium chloride in a sealed test tube, a reversible reaction takes place.
(a)[1 mark]Write a chemical equation to show the decomposition of ammonium chloride on heating.
(b)[1 mark]State the names of the products formed during the decomposition.
(c)[1 mark]Give a reason why the reaction is reversible.
Question 306
1 mark · Easy
Answer and see the solution →State the chemical formula of the white solid that forms when ammonia and hydrogen chloride gases react together in a sealed tube.
Question 307
2 marks · Easy
Answer and see the solution →A reversible reaction occurs in a sealed container. At the start, there are 80 blue squares representing reactant molecules. Every second, one fifth of the blue squares turn yellow (product molecules). After one second, how many blue squares remain? Show your calculation.
Question 308
2 marks · Normal
Answer and see the solution →State what is meant by a sealed container in the context of reversible reactions. Give two essential features.
Question 309
4 marks · Normal
Answer and see the solution →A reversible reaction takes place in a sealed flask. At first, only reactants are present. The forward reaction starts quickly, but slows down over time.
(a)[1 mark]Explain why the rate of the forward reaction decreases as the reaction proceeds.
(b)[1 mark]Describe what is happening with the reverse reaction as the products begin to form.
(c)[1 mark]State what is meant by equilibrium in this context.
(d)[1 mark]Explain why equilibrium can only be reached in a sealed container.
Question 310
3 marks · Normal
Answer and see the solution →Explain, with reasons, why a sealed container is necessary for studying reversible reactions.